1. Field of the Invention
The present invention relates to a method and apparatus for editing a program for an information recording medium playing apparatus.
2. Description of Background Information
As an information recording medium, there is a digital audio disc generally called "compact disc". The recording area of such a digital audio disc is divided into three areas, namely, the lead-in area, program areas, and lead-out area, from the inner radial limit of the recording area. In the read-in area, there is recorded a data group generally called TOC (the disc's Table Of Contents) which includes data indicating how many music programs, or music pieces, there are, how long each music piece lasts, their starting addresses (positions on the disc), and total playing time. Audio information is recorded in the program areas following the lead-in area, and a signal indicating the end of audio information is repeated throughout the lead-out area.
For playing music pieces recorded on such a digital audio disc, i.e. information recording medium, disc players, i.e. information recording medium playing systems, having a function called "random memory selecting function" or "programmed selecting function" have been already developed. Such information recording medium playing systems are structured to edit a playing program determining in what sequence music pieces are to be played, according to music number data input through manual operation using a keyboard, for example. The playing systems are structured to perform, in accordance with the sequence designated by the playing program, operations of selecting a music piece in turn and playing the selected music piece, so that only designated music pieces are played automatically in the programmed sequence.
With such a programmed selecting function of conventional information recording medium playing devices, music pieces recorded on a recording medium such as a digital audio disc can be arbitrary combined for recording on a magnetic tape. In order to avoid a situation that the music piece recorded at an end portion of the magnetic tape intermits at the tape end, it has been necessary for the user of the information recording medium playing apparatus to previously determine which of the music pieces on the recording medium can be recorded on the magnetic tape using information such as the length of the magnetic tape, and the playing time of each music piece, and previously designate the sequence of music pieces to be played. As mentioned above, there has been a drawback that complicated operations are necessary for editing music pieces in the case of the conventional information recording medium playing apparatuses.
For alleviating the difficulty in editing music pieces, an information recording medium playing apparatus has been invented and disclosed in Japanese Patent Application Laid Open No. P62-204488, in which a playing program, including only music pieces which can be played in a designated time period, is edited in response to a command, and the playing operation of the apparatus is performed in accordance with such a playing program.
However, in the case of this prior art information recording medium playing apparatus, if the total playing time obtained by adding up the playing time of each music piece exceeds the designated time period, then the apparatus produces a playing program including only music pieces respectively corresponding to playing times excluding a playing time which has been added lastly. Therefore, if the playing time added lastly is long, the magnetic tape on which the edited music pieces are recorded will have a long silent portion, or no signal portion, in the end portion of the magnetic tape.